I recently proposed to make a set of bluetooth 5.0, two input xmos digital interface, 2.0 the integration of speakers, but in a few systems encountered in the process of the integration of the very distressed, usb digital interface, for example, between bluetooth module and decoder iis (PCM), the process of the decoder output analog signal process,
And to find and solve these problems is the key to have a standard measuring instruments, such as standard signal generator, two or four road oscilloscope, logic analyzer, etc.,
But the problem is coming, my desktop is too small, so a pile of things can not let go, (is poor, actually)
Just as I was upset to mix lab experiment is to find a university, I found this on everything a treasure:
This thing is a virtual oscilloscope, no screen, no processing, various functions all handed over to the CPU to complete, the most important thing is cheap, (for me this poor b 666,)
So, if found such a thing, that is good good study, don't look at it doesn't matter, a look oh, it was also can hang a logic analyzer module! (poor force has been in tears!
Really comfortable, then I looked at the address of the enterprise, dear? Xi 'an software new town? This is not even free mail? So I will contact the business customer service personnel, can get the door pickup and learning the basic method of use the reply after the mood becomes very comfortable, after all, I just graduated from university in 2005, the last time use oscilloscope is in 2008, as a result, I have a bunch of looks very big, so in fact also is three box of stretching things:
And then what? Now that it looks like the thief has been used to open vault door, then start pleasant look at the screen!
Lions in the first place in siege, down under in the group of sharing software, and then installed in the computer, and then the machine frame connected to computer with USB tepyA cable (my computer with wen 10 so you don't have to drive, so I don't know specific how drive outfit,)
Everything is ready, open the oscilloscope software, open the computer in clay pot under their original headset software, set up a 1 KHZ is XuanBo out, then come to a positive XuanBo first:
This is why XuanBo so stable? Don't like using the computer software output? Because I used a from some of the best indicators on audio decoder, so there is no a lot of unnecessary clutter, directly shows a clean 1 k is XuanBo,
After seeing this, the mood becomes very good, and what to do? That is, of course, do the first level of phase comparison between before and after:
Channel for decoder output analog signal, A channel of B for the power output signal, the amplitude of the same, that is because different range and power amplifier potentiometer adjustment problems, in order to image the sporty neatly, middle the pink circle is A_B (X_Y) after calculating the phase difference of visual display, this is no problem, power amplifier, is sure need to deal with time, A delay is normal, no delay that has A problem,
Since this all did, so as a 2.0 sound system, under the condition of the standard signal, it is absolutely not in the same load between left and right channels, phase difference and output level gap, so let's look at the amplifier output after the situation between left and right channels:
Emmm, quite good, the pink stick he is rough and long! Is the burr in some places have let a person not great, but it's not important, after all is a signal generated by the software, even if the move the mouse could affect the 1 k is XuanBo, up and have a look at the signal generator,,, brain broadly pain,
Since the analog part test are no problem, then look at the digital part!!!! This part is, the head hurt again, then you have to look at is not normal, first open the whole:
Whether see dizzy? That's right, i2s signal frequency is too high, so I see n number of data is only a 1 k wave of 1/2, and when I saw this LRCK frequency, I move again, because of LRCK frequency is equal to the digital audio sampling frequency, sampling number=SCLK frequency/sampling frequency (2 x), so, I am the big idea is to give me anything to do with a screen, since the installed screen, to see if it can hold a remote control? Think there's a little excited,
In a word, a sentence with this small scope, the process is greatly simplified, some need multimeter + calculator + draft paper before the scene, under an oscilloscope will no longer need to pass through the complex calculation process to further adjust the circuit, the virtual oscilloscope for desktop small to can only put down the keyboard and display of "I" had a working space as large as possible, as well as the oscilloscope operating requirements of demonstration should be more attractive,